2sk1940.pdf datasheet:

N-channel MOS-FET2SK1940-01FAP-IIA Series 600V 0,75 12A 125W> Features > Outline Drawing- High Speed Switching- Low On-Resistance- No Secondary Breakdown- Low Driving Power- High Voltage- VGS = 30V Guarantee- Avalanche Proof> Applications- Switching Regulators- UPS- DC-DC converters- General Purpose Power Amplifier> Maximum Ratings and Characteristics > Equivalent Circuit- Absolute Maximum Ratings (TC=25C), unless otherwise specifiedItem Symbol Rating UnitDrain-Source-Voltage V 600 VDSDrain-Gate-Voltage (RGS=20K) V 600 VDGRContinous Drain Current ID 12 APulsed Drain Current I 48 AD(puls)Gate-Source-Voltage VGS 30 VMax. Power Dissipation P 125 WDOperating and Storage Temperature Range T 150 CchTstg -55 ~ +150 C- Electrical Characteristics (TC=25C), unless otherwise specifiedItem Symbol Test conditions